Acids, Bases & Dissociation
Strong acids dissociating
- Strong acids will fully dissociate in solution
- For example, when hydrogen chloride (HCl) is dissolved in water 100% of the product will be ions.
- HCl (aq) → H+ (aq) + Cl- (aq)
- In this case hydrogen ions are released, H+ (aq)
- The same applies with strong bases
Strong bases dissociating
- Strong bases will fully dissociate in solution
- NaOH (aq) → Na+ (aq) + OH- (aq)
- In this case hydroxide ions are released, OH- (aq)
Weak acids dissociating
- Weak acids only partially dissociate in solution, only a small percentage of the products will be ions
- In an equilibrium reaction, the products are formed at the same rate as the reactants are used
- This means that at equilibrium, both reactants and products are present in the solution
- For example, ethanoic acid (CH3COOH) is a weak acid that partially dissociates in solution
- CH3COOH (aq) ⇌ CH3COO- (aq) + H+ (aq)
- The same applies with weak bases
Weak bases dissociating
- Weak bases only partially dissociate in solution, only a small percentage of the products will be ions
- An equilibrium is established containing reactants and products
- For example, ethylamine (CH3CH2NH2) is a weak base and will partially dissociate in solution and produce hydroxide ions
- CH3CH2NH2 (aq) + H2O (l) ⇌ CH3CH2NH3+ (aq) + OH- (aq)